Method for forming a semiconductor structure for a gallium nitride channel device

Abstract

A method of forming a semiconductor structure for a III-N semiconductor channel device and a device produced by the method are disclosed. The method includes: (i) forming a buffer structure on a Si-substrate, wherein forming the buffer structure includes: forming a superlattice including at least one superlattice block, each superlattice block including a repetitive sequence of superlattice units, each superlattice unit including a first layer and a second layer formed on the first layer, wherein the first layer is a carbon-doped AlGaN layer and the second layer is a carbon-doped AlGaN layer, wherein x and y differ from each other and 0≤x≤1, 0≤y≤1, and wherein said at least first and second layers are epitaxially grown at a temperature of 980° C. or lower, and (ii) forming a III-N semiconductor channel layer above the buffer structure wherein the channel layer is epitaxially grown at a temperature of 1040° C. or lower and is grown to a thickness of 1 μm or smaller.